Update supported Python versions

.github/workflows/build-book.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8]
+        python-version: ["3.9"]
 
     steps:
     - uses: actions/checkout@v2

.github/workflows/build-test.yml

@@ -11,7 +11,7 @@ jobs:
       fail-fast: false
       matrix:
         name: [ubuntu, macos]
-        python-version: [3.7, 3.8, 3.9]
+        python-version: ["3.8", "3.9", "3.10"]
 
         include:
           - name: ubuntu
@@ -45,7 +45,7 @@ jobs:
           python -m pip list
 
       - name: Lint with flake8
-        if: matrix.name == 'ubuntu' && matrix.python-version == '3.7'
+        if: matrix.name == 'ubuntu' && matrix.python-version == '3.9'
         continue-on-error: true
         run: |
           python -m pip install flake8

setup.py

@@ -25,11 +25,11 @@
         # See https://pypi.python.org/pypi?%3Aaction=list_classifiers
         'Intended Audience :: Science/Research',
         'License :: OSI Approved :: MIT License',
-        'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
         'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
     ],
-    python_requires='>=3.6',
+    python_requires='>=3.8',
     include_package_data=True,
     install_requires=[
         'matplotlib>=2.0.0',